diff --git a/README.md b/README.md
index fc8e7ac..32b54a2 100644
--- a/README.md
+++ b/README.md
@@ -73,21 +73,32 @@ sbackup <command>
 #### 添加备份策略
 
 ```bash
-sbackup add
+sbackup add <source> <dest> [-i ignore_patterns]
 ```
 
-运行后，程序会提示你输入：
-- **备份文件夹**：需要备份的文件夹路径
-- **目标文件夹**：备份文件存放的目标路径
-- **需要忽略的文件夹或文件**：用逗号分隔，例如 `.git,__pycache__,node_modules`
+参数说明：
+- **source**：需要备份的源文件夹路径
+- **dest**：备份文件存放的目标路径
+- **-i, --ignore**：需要忽略的文件或文件夹名称，使用逗号分隔（默认：`.git,__pycache__`）
+
+示例：
+```bash
+sbackup add F:/my_folder F:/backup -i node_modules,.git
+```
 
 #### 删除备份策略
 
 ```bash
-sbackup rm
+sbackup rm <path>
 ```
 
-运行后，程序会提示你输入需要删除备份策略的目标文件夹路径。
+参数说明：
+- **path**：需要删除备份策略的源文件夹路径
+
+示例：
+```bash
+sbackup rm F:/my_folder
+```
 
 #### 查看所有备份策略
 
@@ -184,13 +195,18 @@ python -m unittest discover -s tests -t .
 sbackup/
 ├── main.py              # 程序入口
 ├── sbackup/
-│   ├── __init__.py      # 主模块，处理命令行参数
-│   ├── _compression.py  # 压缩功能实现
-│   └── auto_save.py     # 备份策略管理
+│   ├── __init__.py      # CLI 参数解析和命令分发
+│   ├── __main__.py      # python -m sbackup 入口
+│   ├── config.py        # 配置加载、语言持久化、数据路径
+│   ├── compression.py   # ZIP 压缩功能实现
+│   ├── auto_save.py     # 备份策略管理
+│   └── i18n.py          # 国际化支持
 ├── tests/
 │   └── sbackup/
 │       ├── test_auto_save.py   # 备份策略测试
 │       ├── test_compression.py # 压缩功能测试
+│       ├── test_config.py      # 配置加载测试
+│       ├── test_i18n.py        # 国际化测试
 │       └── test_main.py        # 主模块测试
 ├── config.json          # 配置文件
 └── README.md            # 文档
diff --git a/config.json b/config.json
new file mode 100644
index 0000000..111f559
--- /dev/null
+++ b/config.json
@@ -0,0 +1,3 @@
+{
+    "lang": "en_US"
+}
\ No newline at end of file
diff --git a/main.py b/main.py
index 7abddc5..071b8c4 100644
--- a/main.py
+++ b/main.py
@@ -1,3 +1,4 @@
+import sys
 from sbackup import run
 from sbackup.i18n import t
 
@@ -5,9 +6,10 @@ from sbackup.i18n import t
 def main() -> None:
     """主函数入口"""
     try:
-        run()
+        sys.exit(run())
     except KeyboardInterrupt:
         print(t("exit.message"))
+        sys.exit(130)
 
 
 if __name__ == "__main__":
diff --git a/pyproject.toml b/pyproject.toml
index 544fe59..b48ee80 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,7 +3,7 @@ name = "sbackup"
 version = "1.0.0"
 description = "智能文件夹备份工具，支持增量备份和自定义配置"
 readme = "README.md"
-requires-python = ">=3.12"
+requires-python = ">=3.10"
 license = {text = "GPL-3.0"}
 authors = [
     {name = "xiatianxuan", email = "xiatianxuan2025@163.com"}
diff --git a/sbackup/__init__.py b/sbackup/__init__.py
index 27561ff..a38e8cb 100644
--- a/sbackup/__init__.py
+++ b/sbackup/__init__.py
@@ -4,33 +4,11 @@ import argparse
 import logging
 from sbackup.auto_save import BackupManager
 from sbackup.i18n import set_locale, t
-from sbackup._compression import load_config, save_lang
+from sbackup.config import load_config, save_lang
 
 VERSION = "1.0.0"
 logger = logging.getLogger(__name__)
 
-def detect_lang() -> str:
-    """
-    优先从命令行参数检测语言，其次从配置文件，最后使用默认英语
-    """
-    # 1. 检查命令行参数
-    for i, arg in enumerate(sys.argv):
-        if arg == '--lang' and i + 1 < len(sys.argv):
-            return sys.argv[i + 1]
-        if arg.startswith('--lang='):
-            return arg.split('=', 1)[1]
-            
-    # 2. 检查配置文件
-    try:
-        config = load_config()
-        if config.lang:
-            return config.lang
-    except Exception:
-        pass
-        
-    # 3. 默认语言
-    return "en_US"
-
 EXAMPLES = """示例:
   添加备份策略:
     sbackup add F:/my_folder F:/backup -i node_modules,.git
@@ -70,7 +48,7 @@ Sbackup 帮助您轻松管理多文件夹的备份任务。它采用增量备份
     # 全局参数
     parser.add_argument("--debug", action="store_true", help="开启调试模式，输出详细的运行日志和状态信息")
     parser.add_argument("-h", "--help", action="help", help="显示此帮助信息并退出")
-    parser.add_argument("--lang", default=argparse.SUPPRESS, help="设置界面语言: zh_CN (默认) 或 en_US")
+    parser.add_argument("--lang", default=None, help="设置界面语言: zh_CN (默认) 或 en_US")
     
     subparsers = parser.add_subparsers(dest="command", help="选择要执行的命令")
 
@@ -103,15 +81,18 @@ def parse_path(path_str: str) -> str:
     return os.path.expanduser(path_str.strip())
 
 
-def run() -> None:
+def run() -> int:
+    """
+    主运行函数，返回退出码：0 成功，1 失败
+    """
     parser = get_parser()
     args = parser.parse_args()
 
     # 加载配置以获取默认语言设置
     config = load_config()
-    
+
     # 检查是否显式提供了 --lang 参数
-    if hasattr(args, 'lang'):
+    if args.lang is not None:
         current_lang = args.lang
         # 持久化语言设置
         save_lang(current_lang)
@@ -131,16 +112,16 @@ def run() -> None:
 
     if args.command is None:
         parser.print_help()
-        return
+        return 0
 
     if args.command == "version":
         print(f"""
 Sbackup v{VERSION} — Copyright © 2026 xiatianxuan
 Licensed under GNU GPL v3.0 — https://www.gnu.org/licenses/gpl-3.0.html
 """)
-        return
+        return 0
 
-    manager = BackupManager()
+    manager = BackupManager(data_file=config.data_file)
 
     if args.command == "add":
         source = parse_path(args.source)
@@ -148,12 +129,18 @@ Licensed under GNU GPL v3.0 — https://www.gnu.org/licenses/gpl-3.0.html
         success = manager.add_folder(source, dest, args.ignore)
         if success:
             print(t("cmd.add.success", source=source, dest=dest))
+            return 0
+        return 1
     elif args.command in ("rm", "remove"):
         path = parse_path(args.path)
         success = manager.rm_folder(path)
         if success:
             print(t("cmd.rm.success", path=path))
+            return 0
+        return 1
     elif args.command == "all":
         print(manager.list_folder_table())
+        return 0
     elif args.command == "save":
-        manager.save_folder()
+        manager.execute_backups()
+        return 0
diff --git a/sbackup/__main__.py b/sbackup/__main__.py
new file mode 100644
index 0000000..1bce02f
--- /dev/null
+++ b/sbackup/__main__.py
@@ -0,0 +1,5 @@
+import sys
+from sbackup import run
+
+if __name__ == "__main__":
+    sys.exit(run())
diff --git a/sbackup/auto_save.py b/sbackup/auto_save.py
index 841437c..2eee2e6 100644
--- a/sbackup/auto_save.py
+++ b/sbackup/auto_save.py
@@ -1,19 +1,39 @@
 import os
 import json
+import shutil
 import logging
-from sbackup._compression import Config, ZipfileCompression, load_config
+from dataclasses import dataclass
+from sbackup.config import Config, load_config, get_default_data_file, DEFAULT_SKIP_PATTERNS
+from sbackup.compression import ZipfileCompression
 from sbackup.i18n import t
 
 logger = logging.getLogger(__name__)
 
 
+@dataclass
+class BackupEntry:
+    """备份策略条目"""
+    mtime: float
+    target: str
+    skip_patterns: list[str]
+
+    def to_list(self) -> list:
+        """转为 JSON 兼容的列表格式"""
+        return [self.mtime, self.target, self.skip_patterns]
+
+    @staticmethod
+    def from_list(data: list) -> "BackupEntry":
+        """从 JSON 兼容的列表格式创建"""
+        return BackupEntry(mtime=data[0], target=data[1], skip_patterns=data[2])
+
+
 class BackupManager:
     """
     管理备份策略的类，封装状态和读写操作
     """
-    def __init__(self, data_file: str = "./sbackup.json"):
-        self.data_file: str = data_file
-        self.data: dict = {}
+    def __init__(self, data_file: str = ""):
+        self.data_file: str = data_file or get_default_data_file()
+        self.data: dict[str, list] = {}
         self.load()
 
     def load(self):
@@ -31,6 +51,18 @@ class BackupManager:
                     self.data = json.load(f)
             except json.JSONDecodeError:
                 print(t("warn.json.decode.error", path=self.data_file))
+                # 备份损坏文件，避免数据丢失
+                backup_path = self.data_file + ".bak"
+                try:
+                    shutil.copy2(self.data_file, backup_path)
+                    print(t("warn.json.backup", path=backup_path))
+                except OSError:
+                    # 备份失败时重命名损坏文件，避免下次再次触发
+                    try:
+                        os.rename(self.data_file, self.data_file + ".corrupted")
+                        print(t("warn.json.renamed", path=self.data_file + ".corrupted"))
+                    except OSError:
+                        pass
                 self.data = {}
 
     def save(self, initial: bool = False):
@@ -39,14 +71,24 @@ class BackupManager:
         """
         if not initial:
             logger.debug(f"写入数据文件: {self.data_file}")
-        
+
         data_dir = os.path.dirname(self.data_file)
         if data_dir:
             os.makedirs(data_dir, exist_ok=True)
-            
+
         with open(self.data_file, "w", encoding="utf-8") as f:
             json.dump(self.data, f, ensure_ascii=False, indent=4)
 
+    def _get_entry(self, key: str) -> BackupEntry | None:
+        """获取指定路径的备份策略条目"""
+        raw = self.data.get(key)
+        if raw is None:
+            return None
+        return BackupEntry.from_list(raw)
+
+    def _set_entry(self, key: str, entry: BackupEntry):
+        """设置指定路径的备份策略条目"""
+        self.data[key] = entry.to_list()
 
     def add_folder(
         self,
@@ -58,9 +100,9 @@ class BackupManager:
         添加备份策略
         """
         if skip_patterns is None:
-            skip_patterns = ".git,__pycache__"
-        skip_list = skip_patterns.split(",") if skip_patterns else []
-        
+            skip_patterns = ",".join(DEFAULT_SKIP_PATTERNS)
+        skip_list = [s.strip() for s in skip_patterns.split(",") if s.strip()] if skip_patterns else []
+
         if not os.path.isdir(folder_path):
             print(t("err.folder.invalid", path=folder_path))
             return False
@@ -72,16 +114,20 @@ class BackupManager:
         if abs_path in self.data:
             print(t("info.already.added", path=abs_path))
             return False
-            
-        self.data[abs_path] = [
-            os.stat(abs_path).st_mtime,
-            os.path.abspath(target_folder),
-            skip_list,
-        ]
+
+        try:
+            entry = BackupEntry(
+                mtime=os.stat(abs_path).st_mtime,
+                target=os.path.abspath(target_folder),
+                skip_patterns=skip_list,
+            )
+        except OSError as e:
+            print(t("err.os", error=e))
+            return False
+        self._set_entry(abs_path, entry)
         self.save()
         return True
 
-
     def rm_folder(self, folder_path: str) -> bool:
         """
         删除备份策略
@@ -95,33 +141,63 @@ class BackupManager:
             print(t("warn.no.strategy.found", path=abs_path))
             return False
 
-
-    def save_folder(self):
+    def execute_backups(self):
         """
-        备份所有文件夹
+        执行所有备份策略
         """
         config = load_config()
-        for key, value in list(self.data.items()):
+        backup_count = 0
+        skip_count = 0
+        for key, raw in list(self.data.items()):
             if not os.path.exists(key):
                 print(t("warn.source.missing", path=key))
                 continue
-            if value[0] != os.stat(key).st_mtime:
-                # 使用配置文件中的默认值，但允许覆盖特定项
+            try:
+                current_mtime = os.stat(key).st_mtime
+            except OSError as e:
+                print(t("err.os", error=e))
+                continue
+            entry = BackupEntry.from_list(raw)
+            if entry.mtime != current_mtime:
                 config_instance = Config(
                     folder_path=key,
-                    zipfile_path=value[1],
-                    skip_patterns=value[2],
+                    zipfile_path=entry.target,
+                    skip_patterns=entry.skip_patterns,
                     compression_algorithm=config.compression_algorithm,
                     compression_level=config.compression_level
                 )
-                ZipfileCompression(config_instance).zip_folder()
+                result = ZipfileCompression(config_instance).zip_folder()
+                if result["success"]:
+                    entry.mtime = current_mtime
+                    self._set_entry(key, entry)
+                    backup_count += 1
+            else:
+                skip_count += 1
+        if backup_count > 0:
+            self.save()
+            print(t("cmd.save.completed", count=backup_count))
+        elif skip_count > 0:
+            print(t("cmd.save.uptodate"))
 
+    # 向后兼容别名
+    save_folder = execute_backups
 
     def all_folder(self) -> dict[str, str]:
         """
         查看所有备份策略
         """
-        return {key: value[1] for key, value in self.data.items()}
+        return {key: BackupEntry.from_list(raw).target for key, raw in self.data.items()}
+
+    @staticmethod
+    def _display_width(s: str) -> int:
+        """计算字符串的终端显示宽度（中文字符算2，英文字符算1）"""
+        width = 0
+        for ch in s:
+            if ord(ch) > 0x2E80:
+                width += 2
+            else:
+                width += 1
+        return width
 
     def list_folder_table(self) -> str:
         """
@@ -129,29 +205,27 @@ class BackupManager:
         """
         if not self.data:
             return t("cmd.all.empty")
-        
+
         headers = [t("table.header.source"), t("table.header.dest"), t("table.header.ignore")]
         rows = []
-        for path, info in self.data.items():
-            # 格式化忽略模式
-            skip = ", ".join(info[2]) if info[2] else t("table.cell.none")
-            rows.append([path, info[1], skip])
-        
-        # 计算列宽
-        col_widths = [len(h) for h in headers]
+        for path, raw in self.data.items():
+            entry = BackupEntry.from_list(raw)
+            skip = ", ".join(entry.skip_patterns) if entry.skip_patterns else t("table.cell.none")
+            rows.append([path, entry.target, skip])
+
+        col_widths = [self._display_width(h) for h in headers]
         for row in rows:
             for i, cell in enumerate(row):
-                col_widths[i] = max(col_widths[i], len(cell))
-        
-        # 构建表格
+                col_widths[i] = max(col_widths[i], self._display_width(cell))
+
         fmt = " | ".join(["{:<" + str(w) + "}" for w in col_widths])
         sep = "-+-".join(["-" * w for w in col_widths])
-        
+
         lines = []
         lines.append(fmt.format(*headers))
         lines.append(sep)
         for row in rows:
             lines.append(fmt.format(*row))
-            
+
         return "\n".join(lines)
   
diff --git a/sbackup/_compression.py b/sbackup/compression.py
similarity index 53%
rename from sbackup/_compression.py
rename to sbackup/compression.py
index 850dfd3..f215a22 100644
--- a/sbackup/_compression.py
+++ b/sbackup/compression.py
@@ -1,81 +1,28 @@
 """
-@Time: 2025.12.20
-@Author: codeseed
+压缩模块：ZIP 文件压缩逻辑
 """
 
 import os
-import json
 import zipfile
 from pathlib import Path
 from fnmatch import fnmatch
-from dataclasses import dataclass, field
 from tqdm import tqdm
 from sbackup.i18n import t
+from sbackup.config import Config
 
-DEFAULT_SKIP_PATTERNS = [".git", "__pycache__"]
+# compresslevel 仅对 ZIP_DEFLATED 和 ZIP_BZIP2 有效
+_VALID_COMPRESSLEVEL_ALGORITHMS = {zipfile.ZIP_DEFLATED, zipfile.ZIP_BZIP2}
 
 
-@dataclass
-class Config:
-    folder_path: str = "."
-    zipfile_path: str | None = None
-    skip_patterns: list[str] = field(default_factory=lambda: list(DEFAULT_SKIP_PATTERNS))
-    compression_format: str = "ZIP"
-    compression_algorithm: str = "ZIP_DEFLATED"
-    compression_level: int = 6
-    lang: str = "en_US"
-
-def load_config(config_file: str = "config.json") -> Config:
-    """
-    从配置文件中加载配置
-    """
-    if not os.path.exists(config_file):
-        return Config()
-
-    with open(config_file, "r", encoding="utf-8") as f:
-        config_data = json.load(f)
-
-    compression_config = config_data.get("compression", {})
-    skip_patterns = config_data.get("skip_patterns", DEFAULT_SKIP_PATTERNS)
-    data_file = config_data.get("data_file", "sbackup.json")
-    lang = config_data.get("lang", "en_US")
-
-    return Config(
-        folder_path="",
-        zipfile_path=None,
-        skip_patterns=skip_patterns,
-        compression_format="ZIP",
-        compression_algorithm=compression_config.get("algorithm", "ZIP_DEFLATED"),
-        compression_level=compression_config.get("level", 6),
-        lang=lang
-    )
-
-def save_lang(lang: str, config_file: str = "config.json") -> None:
-    """
-    将语言偏好保存到配置文件
-    """
-    if os.path.exists(config_file):
-        with open(config_file, "r", encoding="utf-8") as f:
-            data = json.load(f)
-    else:
-        data = {}
-    
-    data["lang"] = lang
-    
-    data_dir = os.path.dirname(config_file)
-    if data_dir:
-        os.makedirs(data_dir, exist_ok=True)
-        
-    with open(config_file, "w", encoding="utf-8") as f:
-        json.dump(data, f, ensure_ascii=False, indent=4)
-
 class ZipfileCompression:
     def __init__(self, config: Config) -> None:
         self.folder_path: Path = Path(config.folder_path)
         self.zipfile_path: Path | None = Path(config.zipfile_path) if config.zipfile_path else None
         self.skip_patterns: list[str] = config.skip_patterns
         self.compression_algorithm: int = self._choose_compression_algorithm(config.compression_algorithm)
-        self.compression_level: int = config.compression_level
+        self.compression_level: int | None = self._validate_compresslevel(
+            config.compression_level, self.compression_algorithm
+        )
 
     @staticmethod
     def _choose_compression_algorithm(compression_algorithm: str) -> int:
@@ -91,12 +38,41 @@ class ZipfileCompression:
             case _:
                 return zipfile.ZIP_DEFLATED
 
+    @staticmethod
+    def _validate_compresslevel(level: int, algorithm: int) -> int | None:
+        """校验 compresslevel：仅对 ZIP_DEFLATED 和 ZIP_BZIP2 有效，其他算法不传递该参数"""
+        if algorithm not in _VALID_COMPRESSLEVEL_ALGORITHMS:
+            return None  # zipfile 不接受 compresslevel 时传 None
+        if not (0 <= level <= 9):
+            print(t("warn.invalid.compresslevel", level=level))
+            return 6
+        return level
+
     def _should_ignore(self, name: str) -> bool:
         for pattern in self.skip_patterns:
             if fnmatch(name, pattern):
                 return True
         return False
 
+    def _collect_files(self, folder_path: Path) -> list[tuple[str, str]]:
+        """遍历文件夹收集需要压缩的文件列表，处理权限错误"""
+        files = []
+        try:
+            for dirpath, dirnames, filenames in os.walk(folder_path):
+                try:
+                    dirnames[:] = [d for d in dirnames if not self._should_ignore(d)]
+                    for filename in filenames:
+                        if not self._should_ignore(filename):
+                            files.append((dirpath, filename))
+                except PermissionError as e:
+                    print(t("err.permission", path=dirpath))
+                    continue
+        except PermissionError as e:
+            print(t("err.permission", path=folder_path))
+        except OSError as e:
+            print(t("err.os", error=e))
+        return files
+
     def zip_folder(self) -> dict:
         """
         压缩指定文件夹到 ZIP 文件
@@ -116,32 +92,40 @@ class ZipfileCompression:
             elif zipfile_path.suffix.lower() != ".zip":
                 zipfile_path = zipfile_path.with_name(zipfile_path.name + ".zip")
 
-        # 1. 预先遍历，收集所有需要压缩的文件
-        files_to_compress = []
-        for dirpath, dirnames, filenames in os.walk(folder_path):
-            dirnames[:] = [d for d in dirnames if not self._should_ignore(d)]
-            for filename in filenames:
-                if not self._should_ignore(filename):
-                    files_to_compress.append((dirpath, filename))
-        
+        # ZIP 文件已存在时提示覆盖
+        if zipfile_path.exists():
+            print(t("warn.zip.overwrite", path=zipfile_path))
+
+        # 1. 收集需要压缩的文件（带异常保护）
+        files_to_compress = self._collect_files(folder_path)
         total_files = len(files_to_compress)
         files_count = 0
 
         try:
-            with zipfile.ZipFile(zipfile_path, "w", self.compression_algorithm, compresslevel=self.compression_level) as zipf:
+            zip_kwargs = {"mode": "w", "compression": self.compression_algorithm}
+            if self.compression_level is not None:
+                zip_kwargs["compresslevel"] = self.compression_level
+
+            with zipfile.ZipFile(zipfile_path, **zip_kwargs) as zipf:
                 # 2. 使用 tqdm 显示进度条
                 with tqdm(total=total_files, desc=t("compress.progress"), unit=t("compress.unit")) as pbar:
                     for dirpath, filename in files_to_compress:
                         file_path = Path(dirpath) / filename
-                        arcname = folder_path.parent / file_path.relative_to(folder_path)
-                        zipf.write(file_path, arcname)
-                        pbar.update(1)
-                        files_count += 1
+                        arcname = str(folder_path.name / file_path.relative_to(folder_path)).replace("\\", "/")
+                        try:
+                            zipf.write(file_path, arcname)
+                            pbar.update(1)
+                            files_count += 1
+                        except (FileNotFoundError, PermissionError):
+                            # 文件在遍历后被删除或权限变更，跳过单个文件
+                            continue
 
             size_mb = zipfile_path.stat().st_size / (1024 * 1024)
             # tqdm 清理输出后打印最终结果
             print(t("compress.success", path=zipfile_path, size=size_mb, count=files_count))
             return {"success": True, "files_count": files_count, "size_mb": size_mb}
+        except KeyboardInterrupt:
+            raise
         except PermissionError:
             print(t("err.permission", path=zipfile_path))
             return {"success": False, "files_count": 0, "size_mb": 0.0}
diff --git a/sbackup/config.py b/sbackup/config.py
new file mode 100644
index 0000000..fb06d82
--- /dev/null
+++ b/sbackup/config.py
@@ -0,0 +1,98 @@
+"""
+配置管理模块：配置加载、语言持久化、数据路径
+"""
+
+import os
+import sys
+import json
+import logging
+from dataclasses import dataclass, field
+
+logger = logging.getLogger(__name__)
+
+DEFAULT_SKIP_PATTERNS = [".git", "__pycache__"]
+
+
+def get_default_data_file() -> str:
+    """返回跨平台的默认数据文件路径"""
+    if sys.platform == "win32":
+        base = os.environ.get("APPDATA", os.path.expanduser("~"))
+    elif sys.platform == "darwin":
+        base = os.path.expanduser("~/Library/Application Support")
+    else:
+        base = os.environ.get("XDG_DATA_HOME", os.path.expanduser("~/.local/share"))
+    return os.path.join(base, "sbackup", "sbackup.json")
+
+
+@dataclass
+class Config:
+    folder_path: str = "."
+    zipfile_path: str | None = None
+    skip_patterns: list[str] = field(default_factory=lambda: list(DEFAULT_SKIP_PATTERNS))
+    compression_format: str = "ZIP"
+    compression_algorithm: str = "ZIP_DEFLATED"
+    compression_level: int = 6
+    lang: str = "en_US"
+    data_file: str = field(default_factory=get_default_data_file)
+
+
+def load_config(config_file: str = "config.json") -> Config:
+    """
+    从配置文件中加载配置
+    """
+    if not os.path.exists(config_file):
+        return Config()
+
+    try:
+        with open(config_file, "r", encoding="utf-8") as f:
+            config_data = json.load(f)
+    except json.JSONDecodeError:
+        logger.warning("配置文件 %s 格式错误，使用默认配置", config_file)
+        return Config()
+
+    compression_config = config_data.get("compression", {})
+    skip_patterns = config_data.get("skip_patterns", DEFAULT_SKIP_PATTERNS)
+    data_file = config_data.get("data_file", get_default_data_file())
+    lang = config_data.get("lang", "en_US")
+
+    return Config(
+        folder_path="",
+        zipfile_path=None,
+        skip_patterns=skip_patterns,
+        compression_format="ZIP",
+        compression_algorithm=compression_config.get("algorithm", "ZIP_DEFLATED"),
+        compression_level=compression_config.get("level", 6),
+        lang=lang,
+        data_file=data_file
+    )
+
+
+def save_lang(lang: str, config_file: str = "config.json") -> None:
+    """
+    将语言偏好保存到配置文件
+    """
+    if os.path.exists(config_file):
+        try:
+            with open(config_file, "r", encoding="utf-8") as f:
+                data = json.load(f)
+        except json.JSONDecodeError:
+            logger.warning("配置文件 %s 格式错误，重置为空", config_file)
+            data = {}
+    else:
+        data = {}
+
+    data["lang"] = lang
+
+    data_dir = os.path.dirname(config_file)
+    if data_dir:
+        try:
+            os.makedirs(data_dir, exist_ok=True)
+        except OSError as e:
+            logger.error("无法创建配置目录 %s: %s", data_dir, e)
+            return
+
+    try:
+        with open(config_file, "w", encoding="utf-8") as f:
+            json.dump(data, f, ensure_ascii=False, indent=4)
+    except OSError as e:
+        logger.error("无法写入配置文件 %s: %s", config_file, e)
\ No newline at end of file
diff --git a/sbackup/i18n.py b/sbackup/i18n.py
index 1538a97..a817548 100644
--- a/sbackup/i18n.py
+++ b/sbackup/i18n.py
@@ -1,5 +1,8 @@
 import json
 import os
+import logging
+
+logger = logging.getLogger(__name__)
 
 _current_locale = "zh_CN"
 _translations = {}
@@ -7,8 +10,11 @@ _translations = {}
 # 初始化默认语言包
 _default_file = os.path.join(os.path.dirname(__file__), "locales", "zh_CN.json")
 if os.path.exists(_default_file):
-    with open(_default_file, "r", encoding="utf-8") as f:
-        _translations = json.load(f)
+    try:
+        with open(_default_file, "r", encoding="utf-8") as f:
+            _translations = json.load(f)
+    except (json.JSONDecodeError, OSError) as e:
+        logger.warning("无法加载默认语言包 %s: %s", _default_file, e)
 
 def set_locale(lang: str) -> None:
     """
@@ -18,13 +24,22 @@ def set_locale(lang: str) -> None:
     _current_locale = lang
     locale_file = os.path.join(os.path.dirname(__file__), "locales", f"{lang}.json")
     if os.path.exists(locale_file):
-        with open(locale_file, "r", encoding="utf-8") as f:
-            _translations = json.load(f)
-    else:
-        # 如果找不到语言包，回退到默认中文
-        default_file = os.path.join(os.path.dirname(__file__), "locales", "zh_CN.json")
-        with open(default_file, "r", encoding="utf-8") as f:
-            _translations = json.load(f)
+        try:
+            with open(locale_file, "r", encoding="utf-8") as f:
+                _translations = json.load(f)
+            return
+        except (json.JSONDecodeError, OSError) as e:
+            logger.warning("无法加载语言包 %s: %s", locale_file, e)
+
+    # 回退到默认中文
+    default_file = os.path.join(os.path.dirname(__file__), "locales", "zh_CN.json")
+    if os.path.exists(default_file):
+        try:
+            with open(default_file, "r", encoding="utf-8") as f:
+                _translations = json.load(f)
+        except (json.JSONDecodeError, OSError) as e:
+            logger.warning("无法加载回退语言包 %s: %s", default_file, e)
+            _translations = {}
 
 def t(key: str, **kwargs) -> str:
     """
diff --git a/sbackup/locales/en_US.json b/sbackup/locales/en_US.json
index 81e3e0b..4df4549 100644
--- a/sbackup/locales/en_US.json
+++ b/sbackup/locales/en_US.json
@@ -7,12 +7,18 @@
   "warn.no.strategy.found": "Warning: Backup strategy for {path} not found.",
   "warn.source.missing": "Warning: Source folder does not exist: {path}",
   "warn.json.decode.error": "Warning: Data file {path} is malformed, initializing as empty dict.",
+  "warn.json.backup": "Warning: Corrupted data file backed up to {path}.",
+  "warn.json.renamed": "Warning: Corrupted data file renamed to {path}.",
   "compress.success": "Backup successful: {path} ({size:.2f} MB, {count} files)",
   "compress.progress": "Compressing",
   "compress.unit": "files",
   "err.permission": "Permission denied: Cannot write to '{path}'",
   "err.os": "OS Error: {error}",
   "err.unknown": "Unknown error: {error}",
+  "warn.zip.overwrite": "Warning: Overwriting existing backup file {path}",
+  "warn.invalid.compresslevel": "Warning: Compression level {level} out of range (0-9), using default 6",
+  "cmd.save.uptodate": "All backup strategies are up to date, no backup needed.",
+  "cmd.save.completed": "Backup completed, processed {count} strategy(s).",
   "cmd.all.empty": "No backup strategies configured.",
   "exit.message": "\nExiting.",
   "table.header.source": "Source Folder",
diff --git a/sbackup/locales/zh_CN.json b/sbackup/locales/zh_CN.json
index b234d52..9e49d13 100644
--- a/sbackup/locales/zh_CN.json
+++ b/sbackup/locales/zh_CN.json
@@ -7,12 +7,18 @@
   "warn.no.strategy.found": "警告：未找到 {path} 的备份策略。",
   "warn.source.missing": "警告：源文件夹不存在: {path}",
   "warn.json.decode.error": "警告：数据文件 {path} 格式错误，初始化为空字典。",
+  "warn.json.backup": "警告：已备份损坏的数据文件到 {path}，",
+  "warn.json.renamed": "警告：已将损坏的数据文件重命名为 {path}。",
   "compress.success": "成功备份: {path} ({size:.2f} MB, {count} 个文件)",
   "compress.progress": "正在压缩",
   "compress.unit": "文件",
   "err.permission": "权限不足：无法写入 '{path}'",
   "err.os": "系统错误：{error}",
   "err.unknown": "未知错误：{error}",
+  "warn.zip.overwrite": "警告：将覆盖已有的备份文件 {path}",
+  "warn.invalid.compresslevel": "警告：压缩级别 {level} 超出范围 (0-9)，使用默认值 6",
+  "cmd.save.uptodate": "所有备份策略均已是最新，无需备份。",
+  "cmd.save.completed": "备份完成，共处理 {count} 个策略。",
   "cmd.all.empty": "没有配置任何备份策略。",
   "exit.message": "\n已退出。",
   "table.header.source": "源文件夹路径",
diff --git a/tests/sbackup/test_auto_save.py b/tests/sbackup/test_auto_save.py
index efd83be..08b6e8e 100644
--- a/tests/sbackup/test_auto_save.py
+++ b/tests/sbackup/test_auto_save.py
@@ -7,7 +7,10 @@ import os
 import json
 import tempfile
 import shutil
+import time
+from pathlib import Path
 from sbackup.auto_save import BackupManager
+from sbackup.i18n import t
 
 
 class TestAutoSave(unittest.TestCase):
@@ -62,12 +65,100 @@ class TestAutoSave(unittest.TestCase):
         # 先添加
         self.manager.add_folder(self.source_folder, self.target_folder)
         self.assertIn(os.path.abspath(self.source_folder), self.manager.data)
-        
+
         # 再删除
         result = self.manager.rm_folder(self.source_folder)
         self.assertTrue(result)
         self.assertNotIn(os.path.abspath(self.source_folder), self.manager.data)
 
+    def test_save_folder_updates_mtime(self):
+        """测试执行备份后时间戳被更新，实现增量备份"""
+        # 添加策略
+        self.manager.add_folder(self.source_folder, self.target_folder, "")
+        abs_source = os.path.abspath(self.source_folder)
+        original_mtime = self.manager.data[abs_source][0]
+
+        # 修改源文件夹内容，触发备份条件
+        time.sleep(0.1)
+        (Path(self.source_folder) / "new_file.txt").write_text("new content")
+
+        # 执行备份（使用新方法名 execute_backups）
+        self.manager.execute_backups()
+
+        # 验证 mtime 已更新
+        new_mtime = self.manager.data[abs_source][0]
+        self.assertNotEqual(original_mtime, new_mtime, "备份后 mtime 应被更新")
+        self.assertEqual(new_mtime, os.stat(abs_source).st_mtime)
+
+        # 验证数据已持久化
+        self.manager.load()
+        self.assertEqual(self.manager.data[abs_source][0], new_mtime)
+
+    def test_execute_backups_alias(self):
+        """测试 save_folder 向后兼容别名"""
+        self.assertTrue(hasattr(self.manager, "save_folder"))
+        # 验证 save_folder 指向 execute_backups 的底层函数
+        self.assertIs(
+            self.manager.save_folder.__func__,
+            self.manager.execute_backups.__func__
+        )
+
+    def test_add_folder_skip_patterns_stripped(self):
+        """测试忽略模式中的空格被正确去除"""
+        result = self.manager.add_folder(
+            self.source_folder, self.target_folder, " .git , node_modules "
+        )
+        self.assertTrue(result)
+        abs_source = os.path.abspath(self.source_folder)
+        skip_list = self.manager.data[abs_source][2]
+        self.assertEqual(skip_list, [".git", "node_modules"])
+
+    def test_add_duplicate_folder(self):
+        """测试重复添加同一文件夹应失败"""
+        result1 = self.manager.add_folder(self.source_folder, self.target_folder)
+        self.assertTrue(result1)
+        result2 = self.manager.add_folder(self.source_folder, self.target_folder)
+        self.assertFalse(result2)
+        abs_source = os.path.abspath(self.source_folder)
+        self.assertEqual(len(self.manager.data), 1)
+
+    def test_rm_nonexistent_folder(self):
+        """测试删除不存在的策略应失败"""
+        result = self.manager.rm_folder("/nonexistent/path")
+        self.assertFalse(result)
+
+    def test_add_invalid_source(self):
+        """测试添加无效源目录应失败"""
+        result = self.manager.add_folder("/nonexistent/path", self.target_folder)
+        self.assertFalse(result)
+
+    def test_add_invalid_dest(self):
+        """测试添加无效目标目录应失败"""
+        result = self.manager.add_folder(self.source_folder, "/nonexistent/path")
+        self.assertFalse(result)
+
+    def test_save_missing_source(self):
+        """测试源文件夹不存在时的 save 行为"""
+        # 手动构造一条源文件夹不存在的记录
+        self.manager.data["/nonexistent/source"] = [0.0, self.target_folder, []]
+        self.manager.save()
+        # save_folder 应打印警告并跳过，不抛出异常
+        self.manager.save_folder()
+        # 数据应保持不变（不会被删除）
+        self.assertIn("/nonexistent/source", self.manager.data)
+
+    def test_list_folder_table_empty(self):
+        """测试空策略时表格返回提示文本"""
+        text = self.manager.list_folder_table()
+        self.assertEqual(text, t("cmd.all.empty"))
+
+    def test_all_folder(self):
+        """测试 all_folder 返回正确字典"""
+        self.manager.add_folder(self.source_folder, self.target_folder)
+        result = self.manager.all_folder()
+        abs_source = os.path.abspath(self.source_folder)
+        self.assertEqual(result[abs_source], os.path.abspath(self.target_folder))
+
 
 if __name__ == "__main__":
     unittest.main()
\ No newline at end of file
diff --git a/tests/sbackup/test_compression.py b/tests/sbackup/test_compression.py
index 2f58620..6dd80c3 100644
--- a/tests/sbackup/test_compression.py
+++ b/tests/sbackup/test_compression.py
@@ -1,5 +1,5 @@
 """
-单元测试 for sbackup._compression 模块
+单元测试 for sbackup.compression 模块
 """
 import unittest
 import os
@@ -7,7 +7,9 @@ import shutil
 import zipfile
 from pathlib import Path
 from unittest.mock import patch
-from sbackup._compression import Config, ZipfileCompression
+from sbackup.config import Config
+from sbackup.compression import ZipfileCompression
+from sbackup.i18n import t
 
 
 class TestCompression(unittest.TestCase):
@@ -18,7 +20,7 @@ class TestCompression(unittest.TestCase):
         (Path(self.test_dir) / "file1.txt").write_text("test content 1")
         (Path(self.test_dir) / "subdir").mkdir()
         (Path(self.test_dir) / "subdir" / "file2.txt").write_text("test content 2")
-        
+
         self.zip_path = "test.zip"
         if os.path.exists(self.zip_path):
             os.remove(self.zip_path)
@@ -38,9 +40,81 @@ class TestCompression(unittest.TestCase):
         )
         compressor = ZipfileCompression(config)
         compressor.zip_folder()
-        
+
         self.assertTrue(os.path.exists(self.zip_path))
         self.assertGreater(os.path.getsize(self.zip_path), 0)
 
+    def test_zip_internal_path_structure(self):
+        """测试 ZIP 内部路径结构正确（以文件夹名开头，而非绝对路径）"""
+        config = Config(
+            folder_path=self.test_dir,
+            zipfile_path=self.zip_path,
+        )
+        compressor = ZipfileCompression(config)
+        compressor.zip_folder()
+
+        with zipfile.ZipFile(self.zip_path, "r") as zf:
+            namelist = zf.namelist()
+            for name in namelist:
+                self.assertTrue(
+                    name.startswith("test_data/"),
+                    f"ZIP 内部路径 '{name}' 应以 'test_data/' 开头"
+                )
+
+    def test_zip_respects_skip_patterns(self):
+        """测试压缩时正确忽略匹配的文件"""
+        (Path(self.test_dir) / ".gitignore").write_text("ignore")
+        config = Config(
+            folder_path=self.test_dir,
+            zipfile_path=self.zip_path,
+            skip_patterns=[".gitignore"],
+        )
+        compressor = ZipfileCompression(config)
+        result = compressor.zip_folder()
+
+        self.assertTrue(result["success"])
+        with zipfile.ZipFile(self.zip_path, "r") as zf:
+            namelist = zf.namelist()
+            self.assertNotIn("test_data/.gitignore", namelist)
+
+    @patch("builtins.print")
+    def test_compresslevel_out_of_range(self, mock_print):
+        """测试压缩级别超出范围时回退到默认值"""
+        config = Config(
+            folder_path=self.test_dir,
+            zipfile_path=self.zip_path,
+            compression_level=99,
+        )
+        compressor = ZipfileCompression(config)
+        # compresslevel 应回退到 6
+        self.assertEqual(compressor.compression_level, 6)
+
+    def test_compresslevel_none_for_stored(self):
+        """测试 ZIP_STORED 算法不传递 compresslevel"""
+        config = Config(
+            folder_path=self.test_dir,
+            zipfile_path=self.zip_path,
+            compression_algorithm="ZIP_STORED",
+            compression_level=6,
+        )
+        compressor = ZipfileCompression(config)
+        self.assertIsNone(compressor.compression_level)
+
+    @patch("builtins.print")
+    def test_zip_overwrite_warning(self, mock_print):
+        """测试 ZIP 文件已存在时输出覆盖警告"""
+        config = Config(
+            folder_path=self.test_dir,
+            zipfile_path=self.zip_path,
+        )
+        compressor = ZipfileCompression(config)
+        # 第一次压缩
+        compressor.zip_folder()
+        # 第二次压缩（文件已存在）
+        compressor.zip_folder()
+        printed = " ".join(str(call) for call in mock_print.call_args_list)
+        self.assertIn(t("warn.zip.overwrite").split("{")[0], printed)
+
+
 if __name__ == "__main__":
     unittest.main()
\ No newline at end of file
diff --git a/tests/sbackup/test_config.py b/tests/sbackup/test_config.py
index f28fae8..267fa73 100644
--- a/tests/sbackup/test_config.py
+++ b/tests/sbackup/test_config.py
@@ -1,12 +1,12 @@
 """
-单元测试 for sbackup._compression.load_config 函数
+单元测试 for sbackup.config 模块（load_config / save_lang）
 """
 
 import unittest
 import os
 import tempfile
 import json
-from sbackup._compression import load_config, Config
+from sbackup.config import load_config, save_lang, Config
 
 
 class TestConfig(unittest.TestCase):
@@ -55,7 +55,8 @@ class TestConfig(unittest.TestCase):
         """
         测试从默认配置文件中加载配置
         """
-        # 创建默认配置文件
+        # 在临时目录中创建默认配置文件（而非项目根目录）
+        default_config = os.path.join(self.test_dir, "config.json")
         config_data = {
             "compression": {
                 "algorithm": "ZIP_DEFLATED",
@@ -64,19 +65,14 @@ class TestConfig(unittest.TestCase):
             "skip_patterns": [".git", "__pycache__"],
             "data_file": "sbackup.json"
         }
-        with open("config.json", "w", encoding="utf-8") as f:
+        with open(default_config, "w", encoding="utf-8") as f:
             json.dump(config_data, f, ensure_ascii=False, indent=4)
 
-        # 加载配置
-        config = load_config()
+        config = load_config(default_config)
 
-        # 验证配置
         self.assertEqual(config.compression_algorithm, "ZIP_DEFLATED")
         self.assertEqual(config.compression_level, 6)
         self.assertEqual(config.skip_patterns, [".git", "__pycache__"])
-        
-        # 清理默认配置文件
-        os.remove("config.json")
 
     def test_load_config_from_nonexistent_file(self):
         """
@@ -90,6 +86,72 @@ class TestConfig(unittest.TestCase):
         self.assertEqual(config.compression_level, 6)
         self.assertEqual(config.skip_patterns, [".git", "__pycache__"])
 
+    def test_load_config_malformed_json(self):
+        """测试配置文件 JSON 格式错误时使用默认配置"""
+        malformed_config = os.path.join(self.test_dir, "bad_config.json")
+        with open(malformed_config, "w", encoding="utf-8") as f:
+            f.write("{invalid json content!!!")
+
+        config = load_config(malformed_config)
+        self.assertEqual(config.compression_algorithm, "ZIP_DEFLATED")
+        self.assertEqual(config.compression_level, 6)
+
+
+class TestSaveLang(unittest.TestCase):
+    def setUp(self):
+        self.test_dir = tempfile.mkdtemp()
+        self.config_file = os.path.join(self.test_dir, "config.json")
+
+    def tearDown(self):
+        if os.path.exists(self.test_dir):
+            import shutil
+            shutil.rmtree(self.test_dir)
+
+    def test_save_lang_creates_new_file(self):
+        """测试 save_lang 在配置文件不存在时创建新文件"""
+        save_lang("zh_CN", self.config_file)
+
+        self.assertTrue(os.path.exists(self.config_file))
+        with open(self.config_file, "r", encoding="utf-8") as f:
+            data = json.load(f)
+        self.assertEqual(data["lang"], "zh_CN")
+
+    def test_save_lang_updates_existing_file(self):
+        """测试 save_lang 在已有配置文件中更新语言字段"""
+        # 先写入已有配置
+        with open(self.config_file, "w", encoding="utf-8") as f:
+            json.dump({"compression": {"algorithm": "ZIP_STORED", "level": 3}}, f)
+
+        save_lang("en_US", self.config_file)
+
+        with open(self.config_file, "r", encoding="utf-8") as f:
+            data = json.load(f)
+        self.assertEqual(data["lang"], "en_US")
+        # 原有配置应保留
+        self.assertEqual(data["compression"]["algorithm"], "ZIP_STORED")
+        self.assertEqual(data["compression"]["level"], 3)
+
+    def test_save_lang_overwrites_existing_lang(self):
+        """测试 save_lang 覆盖已有的语言设置"""
+        with open(self.config_file, "w", encoding="utf-8") as f:
+            json.dump({"lang": "zh_CN"}, f)
+
+        save_lang("en_US", self.config_file)
+
+        with open(self.config_file, "r", encoding="utf-8") as f:
+            data = json.load(f)
+        self.assertEqual(data["lang"], "en_US")
+
+    def test_save_lang_with_subdirectory(self):
+        """测试 save_lang 在子目录中创建配置文件"""
+        subdir_config = os.path.join(self.test_dir, "sub", "config.json")
+        save_lang("zh_CN", subdir_config)
+
+        self.assertTrue(os.path.exists(subdir_config))
+        with open(subdir_config, "r", encoding="utf-8") as f:
+            data = json.load(f)
+        self.assertEqual(data["lang"], "zh_CN")
+
 
 if __name__ == "__main__":
     unittest.main()
\ No newline at end of file
diff --git a/tests/sbackup/test_i18n.py b/tests/sbackup/test_i18n.py
new file mode 100644
index 0000000..6e6bc8c
--- /dev/null
+++ b/tests/sbackup/test_i18n.py
@@ -0,0 +1,73 @@
+"""
+单元测试 for sbackup.i18n 模块
+"""
+
+import unittest
+import os
+import json
+import tempfile
+from sbackup import i18n
+
+
+class TestI18n(unittest.TestCase):
+    def setUp(self):
+        """保存原始状态"""
+        self._orig_locale = i18n._current_locale
+        self._orig_trans = i18n._translations.copy()
+
+    def tearDown(self):
+        """恢复原始状态"""
+        i18n._current_locale = self._orig_locale
+        i18n._translations = self._orig_trans
+
+    def test_set_locale_existing(self):
+        """测试设置为存在的语言包"""
+        i18n.set_locale("zh_CN")
+        self.assertEqual(i18n._current_locale, "zh_CN")
+        self.assertIn("cmd.add.success", i18n._translations)
+
+    def test_set_locale_fallback(self):
+        """测试设置不存在的语言包时回退到中文"""
+        i18n.set_locale("nonexistent_lang")
+        self.assertEqual(i18n._current_locale, "nonexistent_lang")
+        self.assertIn("cmd.add.success", i18n._translations)
+
+    def test_t_basic(self):
+        """测试基础翻译获取"""
+        i18n.set_locale("zh_CN")
+        text = i18n.t("cmd.add.success", source="/a", dest="/b")
+        self.assertIn("/a", text)
+        self.assertIn("/b", text)
+
+    def test_t_missing_key(self):
+        """测试缺失键名时返回键名本身"""
+        i18n.set_locale("zh_CN")
+        text = i18n.t("this.key.does.not.exist")
+        self.assertEqual(text, "this.key.does.not.exist")
+
+    def test_t_no_kwargs(self):
+        """测试无格式化参数时返回原文"""
+        i18n.set_locale("en_US")
+        text = i18n.t("cmd.all.empty")
+        self.assertEqual(text, "No backup strategies configured.")
+
+    def test_t_format_error(self):
+        """测试格式化参数不匹配时返回原文"""
+        i18n.set_locale("zh_CN")
+        text = i18n.t("cmd.add.success", wrong_key="value")
+        # 应返回未格式化的原文
+        self.assertEqual(text, "备份策略添加成功: {source} -> {dest}")
+
+    def test_language_switch_returns_correct_text(self):
+        """测试切换语言后 t() 返回对应语言的文本"""
+        i18n.set_locale("zh_CN")
+        zh_text = i18n.t("cmd.all.empty")
+        self.assertEqual(zh_text, "没有配置任何备份策略。")
+
+        i18n.set_locale("en_US")
+        en_text = i18n.t("cmd.all.empty")
+        self.assertEqual(en_text, "No backup strategies configured.")
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/sbackup/test_main.py b/tests/sbackup/test_main.py
index 15ccf24..08e67fb 100644
--- a/tests/sbackup/test_main.py
+++ b/tests/sbackup/test_main.py
@@ -3,10 +3,29 @@
 """
 import unittest
 import sys
+import os
+import logging
+import tempfile
+import shutil
 from unittest.mock import patch
+from sbackup.i18n import t
 
 
 class TestMain(unittest.TestCase):
+    def setUp(self):
+        self.test_dir = tempfile.mkdtemp()
+        self.original_argv = sys.argv.copy()
+        # 保存并重置 logging 状态
+        self._root_handlers = logging.root.handlers[:]
+        self._root_level = logging.root.level
+
+    def tearDown(self):
+        sys.argv = self.original_argv
+        shutil.rmtree(self.test_dir, ignore_errors=True)
+        # 恢复 logging 状态
+        logging.root.handlers = self._root_handlers
+        logging.root.setLevel(self._root_level)
+
     @patch("builtins.print")
     def test_version_command(self, mock_print):
         """测试 version 命令"""
@@ -15,5 +34,71 @@ class TestMain(unittest.TestCase):
         run()
         mock_print.assert_called()
 
+    @patch("argparse.ArgumentParser.print_help")
+    def test_no_command_shows_help(self, mock_help):
+        """测试无命令时显示帮助"""
+        sys.argv = ["sbackup"]
+        from sbackup import run
+        run()
+        mock_help.assert_called_once()
+
+    @patch("builtins.print")
+    def test_add_command_invalid_source(self, mock_print):
+        """测试 add 命令传入无效源目录"""
+        sys.argv = ["sbackup", "--lang", "en_US", "add", "/nonexistent/path", "/tmp"]
+        from sbackup import run
+        run()
+        printed = " ".join(str(call) for call in mock_print.call_args_list)
+        self.assertIn(t("err.folder.invalid").split("{")[0].strip(), printed)
+
+    @patch("builtins.print")
+    def test_rm_command_nonexistent(self, mock_print):
+        """测试 rm 命令删除不存在的策略"""
+        sys.argv = ["sbackup", "--lang", "en_US", "rm", "/nonexistent/path"]
+        from sbackup import run
+        run()
+        printed = " ".join(str(call) for call in mock_print.call_args_list)
+        self.assertIn(t("warn.no.strategy.found").split("{")[0].strip(), printed)
+
+    @patch("builtins.print")
+    def test_all_command_empty(self, mock_print):
+        """测试 all 命令在无策略时输出提示"""
+        os.chdir(self.test_dir)
+        sys.argv = ["sbackup", "--lang", "en_US", "all"]
+        from sbackup import run
+        run()
+        printed = " ".join(str(call) for call in mock_print.call_args_list)
+        self.assertIn(t("cmd.all.empty"), printed)
+
+    @patch("builtins.print")
+    def test_lang_switch(self, mock_print):
+        """测试 --lang 参数切换语言"""
+        os.chdir(self.test_dir)
+        sys.argv = ["sbackup", "--lang", "en_US", "all"]
+        from sbackup import run
+        run()
+        printed = " ".join(str(call) for call in mock_print.call_args_list)
+        self.assertIn("No backup strategies configured", printed)
+
+    @patch("builtins.print")
+    def test_debug_mode_sets_logging(self, mock_print):
+        """测试 --debug 参数开启 DEBUG 日志级别"""
+        os.chdir(self.test_dir)
+        sys.argv = ["sbackup", "--debug", "--lang", "en_US", "all"]
+        from sbackup import run
+        run()
+        self.assertEqual(logging.root.level, logging.DEBUG)
+
+    @patch("builtins.print")
+    def test_no_debug_keeps_default_logging(self, mock_print):
+        """测试无 --debug 时日志级别保持默认"""
+        os.chdir(self.test_dir)
+        logging.root.setLevel(logging.WARNING)
+        sys.argv = ["sbackup", "--lang", "en_US", "all"]
+        from sbackup import run
+        run()
+        self.assertEqual(logging.root.level, logging.WARNING)
+
+
 if __name__ == "__main__":
     unittest.main()
\ No newline at end of file